# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

from __future__ import absolute_import, print_function, unicode_literals

import copy
import logging

from . import transform
from ..util.yaml import load_yaml

logger = logging.getLogger(__name__)


class TestTask(transform.TransformTask):
    """
    A task implementing a Gecko test.
    """

    @classmethod
    def get_inputs(cls, kind, path, config, params, loaded_tasks):

        # the kind on which this one depends
        if len(config.get('kind-dependencies', [])) != 1:
            raise Exception("TestTask kinds must have exactly one item in kind-dependencies")
        dep_kind = config['kind-dependencies'][0]

        # get build tasks, keyed by build platform
        builds_by_platform = cls.get_builds_by_platform(dep_kind, loaded_tasks)

        # get the test platforms for those build tasks
        test_platforms_cfg = load_yaml(path, 'test-platforms.yml')
        test_platforms = cls.get_test_platforms(test_platforms_cfg, builds_by_platform)

        # expand the test sets for each of those platforms
        test_sets_cfg = load_yaml(path, 'test-sets.yml')
        test_platforms = cls.expand_tests(test_sets_cfg, test_platforms)

        # load the test descriptions
        test_descriptions = load_yaml(path, 'tests.yml')

        # generate all tests for all test platforms
        for test_platform_name, test_platform in test_platforms.iteritems():
            for test_name in test_platform['test-names']:
                test = copy.deepcopy(test_descriptions[test_name])
                test['build-platform'] = test_platform['build-platform']
                test['test-platform'] = test_platform_name
                test['build-label'] = test_platform['build-label']
                test['test-name'] = test_name

                logger.debug("Generating tasks for {} test {} on platform {}".format(
                    kind, test_name, test['test-platform']))
                yield test

    @classmethod
    def get_builds_by_platform(cls, dep_kind, loaded_tasks):
        """Find the build tasks on which tests will depend, keyed by
        platform/type.  Returns a dictionary mapping build platform to task
        label."""
        builds_by_platform = {}
        for task in loaded_tasks:
            if task.kind != dep_kind:
                continue

            build_platform = task.attributes.get('build_platform')
            build_type = task.attributes.get('build_type')
            if not build_platform or not build_type:
                continue
            platform = "{}/{}".format(build_platform, build_type)
            if platform in builds_by_platform:
                raise Exception("multiple build jobs for " + platform)
            builds_by_platform[platform] = task.label
        return builds_by_platform

    @classmethod
    def get_test_platforms(cls, test_platforms_cfg, builds_by_platform):
        """Get the test platforms for which test tasks should be generated,
        based on the available build platforms.  Returns a dictionary mapping
        test platform to {test-set, build-platform, build-label}."""
        test_platforms = {}
        for test_platform, cfg in test_platforms_cfg.iteritems():
            build_platform = cfg['build-platform']
            if build_platform not in builds_by_platform:
                logger.warning(
                    "No build task with platform {}; ignoring test platform {}".format(
                        build_platform, test_platform))
                continue
            test_platforms[test_platform] = {
                'test-set': cfg['test-set'],
                'build-platform': build_platform,
                'build-label': builds_by_platform[build_platform],
            }
        return test_platforms

    @classmethod
    def expand_tests(cls, test_sets_cfg, test_platforms):
        """Expand the test sets in `test_platforms` out to sets of test names.
        Returns a dictionary like `get_test_platforms`, with an additional
        `test-names` key for each test platform, containing a set of test
        names."""
        rv = {}
        for test_platform, cfg in test_platforms.iteritems():
            test_set = cfg['test-set']
            if test_set not in test_sets_cfg:
                raise Exception(
                    "Test set '{}' for test platform {} is not defined".format(
                        test_set, test_platform))
            test_names = test_sets_cfg[test_set]
            rv[test_platform] = cfg.copy()
            rv[test_platform]['test-names'] = test_names
        return rv
